devel/py-python-gitlab: Update to 4.1.1

• Update to 4.1.1 [1] [2] [3]
• Move to a pep517 project

[1] https://github.com/python-gitlab/python-gitlab/releases/tag/v4.1.1
[2] https://github.com/python-gitlab/python-gitlab/releases/tag/v4.1.0
[3] https://github.com/python-gitlab/python-gitlab/releases/tag/v4.0.0

PR: 274922